Detroits for this axle, like the 14B, mount inside the stock carrier.
Did some research on the Eaton site. Since this carrier is 2-piece, the locker is one of:
225SL58A, 225SL58B, 225SL58C, 225SL58D For Dana 70HD, 35 spline applications.
The B and D suffixes are for 4.10 and down. Since it was in an axle with 4.56 gears it is either the A or C, and since the C is for D70U, the locker inside the case is certainly the 225SL58A. 1.5" diameter axle shafts and 35 splines.
I don't really want to split the carrier if I don't know how to put it back together. My mechanic friend found the following engraved on the end of the cross-pin:
67564 TC
Eaton 9J S
Haven't found any web searches for those marks.